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1
Kerfs, Jeremy N. "Models for Pedestrian Trajectory Prediction and Navigation in Dynamic Environments." DigitalCommons@CalPoly, 2017. https://digitalcommons.calpoly.edu/theses/1716.
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Robots are no longer constrained to cages in factories and are increasingly taking on roles alongside humans. Before robots can accomplish their tasks in these dynamic environments, they must be able to navigate while avoiding collisions with pedestrians or other robots. Humans are able to move through crowds by anticipating the movements of other pedestrians and how their actions will influence others; developing a method for predicting pedestrian trajectories is a critical component of a robust robot navigation system. A current state-of-the-art approach for predicting pedestrian trajectories is Social-LSTM, which is a recurrent neural network that incorporates information about neighboring pedestrians to learn how people move cooperatively around each other. This thesis extends and modifies that model to output parameters for a multimodal distribution, which better captures the uncertainty inherent in pedestrian movements. Additionally, four novel architectures for representing neighboring pedestrians are proposed; these models are more general than current trajectory prediction systems and have fewer hyper-parameters. In both simulations and real-world datasets, the multimodal extension significantly increases the accuracy of trajectory prediction. One of the new neighbor representation architectures achieves state-of-the-art results while reducing the number of both parameters and hyper-parameters compared to existing solutions. Two techniques for incorporating the trajectory predictions into a planning system are also developed and evaluated on a real-world dataset. Both techniques plan routes that include fewer near-collisions than algorithms that do not use trajectory predictions. Finally, a Python library for Agent-Based-Modeling and crowd simulation is presented to aid in future research.
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Grachek, Adam. "Individualized Pedestrian and Micromobility Routing Incorporating Static and Dynamic Parameters." Thesis, Linköpings universitet, Kommunikations- och transportsystem, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177784.
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This project seeks to demonstrate routing optimization that would allow pedestrian and micromobility user groups to select and prioritize different route features according to their preferences. Through the creation of a routing demonstrator that considers both static and dynamic parameters in the form of pavement quality, elevation climb, travel time, and air quality, along with user-specified weights for their prioritization of each of these parameters, a number of routes were created and mapped to qualitatively compare against routes representing only a shortest path.Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet
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Hallak, Neilson John Peter. "Numerical and experimental dynamic analyses of the Vega Pedestrian bridge including seasonal effects." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-255536.
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As timber structures become increasingly relevant and sought after – since they enable improvements in building time while reducing a structure’s life cycle impacts – streamlining their design can have meaningful economic and environmental implications. For timber footbridges, its design is frequently governed by serviceability criteria linked to excessive vibrations. To address this in design, it is necessary to correctly characterize the structure’s dynamic properties and understand what the leading parameters in its behaviour are. This thesis studied an existing timber arch footbridge, aiming to evaluate its dynamic behaviour both with experimental measurements and with theoretical models. The influence of temperature change over different seasons was considered, particularly around its effect on the asphalt layer – whose stiffness is highly correlated to temperature. The experimental results showed high correlation between temperature and natural frequencies: a variation of +21°C reduced the natural frequency for the 1st transverse mode of the deck by as much as 30.6% while the 1st vertical mode was reduced by 17.7% (variation of 0.029Hz/°C). The damping ratio was also measured, though a definitive correlation between its value and temperature was not identified. This change in behaviour cannot be explained by the influence of the asphalt layer alone however, as there is a high degree of uncertainty around many other components of the bridge and their interactions, such as the connections. Thus, to fully characterize the influence of each component with changing temperature, further experimental tests would have to be performed, or simpler structures with fewer connections should be considered. In designing a new structure, considering the asphalt layer as an added mass is a straightforward way to treat this material at the most critical condition (i.e. no contribution to stiffness). This strategy lead to sufficiently similar results between the computational model and the experimental results at warm temperatures. The asphalt stiffness could perhaps be considered for the 1st transverse mode of the deck, since it is in this mode that the asphalt layer plays its largest contribution.
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FAN, YINA, and FANGZHOU LIU. "Dynamic Analysis of Long Span Footbridges." Thesis, KTH, Bro- och stålbyggnad, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-169183.
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A footbridge in Slussen is planned to be built and will connect the area of Gamla Stan with Sodermalm. As an increasing number of footbridges with large span tend to become more flexible and light these days, the corresponding dynamic problems due to decreased stiffness and mass draw much more attention. Specifically speaking, reduced stiffness and mass lead to smaller natural frequencies, which make the structure more sensitive to pedestrian-induced loading, especially in lateral direction. Fortunately, in this master thesis, only the vibration in vertical direction is focused due to that the footbridge in Slussen project uses enough lateral bracings to make sure that the safety of lateral vibration is kept at an acceptable level. In order to analyze dynamic response of the footbridge, the real footbridge structure is converted into a FE model by the commercial software LUSAS. In this thesis, four different kinds of critical standards are introduced, which are Sétra [8], Swedish standard Bro 2004 [9], ISO 10137 [5] and Eurocode respectively. By comparing these four criteria, Sétra and Eurocode are finally chosen to be the standard and guidelines for this project. They give the basic theories about how to model the pedestrian loading and provide critical values to check the accelerations in both vertical and lateral direction. By using FE software LUSAS, natural frequencies of the footbridge and the corresponding mode shapes can be calculated directly. Then, according to these results and relevant theories introduced by Sétra, the pedestrian loading can be modeled and the acceleration response of any specific mode can be obtained as well. Finally, based on the worst case with excessive acceleration, the methods to reduce dynamic response will be presented. Commonly, there are two ways to reduce acceleration response. One method is to increase the stiffness of the structure. However, the increased stiffness is always accompanied with increased mass of the structure. Because of this reason, the other way that installing dampers is widely used in recent years. In this thesis, the tuned mass dampers (TMDs) are introduced in detail as well as the information about the design principles of it. With important parameters known, TMDs can be added to the model to check how the accelerations can be reduced.
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IBISEVIC, AIDA, and HASANHÜSEYIN UGUR. "Numerical and experimental dynamic analyses of Hägernäs pedestrian bridge : Including seasonal effects." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254550.
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Wood as a construction material has in recent years increased, in particular concerningpedestrian bridges. By utilizing wood, the ecological footprint can be reduced,and the material can be designed to comply with the increasing aesthetic demandbridge designers are facing. However, as the material weighs little with respect toits bearing capacity, combined with design becoming more slender, human inducedvibrations are becoming a problem.Having this in mind, the objective of the thesis is to conduct a case study on anexisting timber pedestrian bridge and assess its dynamic parameters by means ofexperiential testing and numerical modelling. The case study concerns the Hägernäsbridge, an arch bridge located in Hägernäs, Täby. The thesis also considers seasonaleffects by conducting experiments on two separate occasions. In addition, the thesisevaluates influencing parameters on the dynamic behaviour by conducting a sensitivityanalysis. To aid the above mentioned objective, a literature review coveringsimilar type of analysis is conducted. The literature review also studies the seasonaleffect, mainly from the asphalt layer, as its stiffness contribution is temperaturedependant.The results from the dynamic parameters showed that not all modes fall above therecommended values concerning damping ratio (with values above 1-1.5%). However,all modes fulfill design criteria concerning the magnitude of the natural frequencies.Furthermore, results showed that the natural frequencies are highly temperaturedependant. The measured values during warm weather (+17C) resulted in lowervalues than those from the cold weather experiment (-10C). Moreover, the greatestdifference, by 21% was on the 1st transverse mode and the lower difference was onthe 1st vertical mode, that decreased by merely 5%. Moreover, the damping ratiowas calculated and it was not possible to find any correlation between warm andcold temperature. Instead, decreased temperature caused some modes to increase indamping ratio and others to decrease. The most affected mode was once again the1st transverse mode which increased by 146% going from warm to cold temperature
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Hallak, Neilson John. "Numerical and experimental dynamic analyses of the Vega Pedestrian bridge including seasonal effects." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254385.
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As timber structures become increasingly relevant and sought after – since they enable improvements in building time while reducing a structure’s life cycle impacts – streamlining their design can have meaningful economic and environmental implications.For timber footbridges, its design is frequently governed by serviceability criteria linked to excessive vibrations. To address this in design, it is necessary to correctly characterize the structure’s dynamic properties and understand what the leading parameters in its behaviour are.This thesis studied an existing timber arch footbridge, aiming to evaluate its dynamic behaviour both with experimental measurements and with theoretical models. The influence of temperature change over different seasons was considered, particularly around its effect on the asphalt layer – whose stiffness is highly correlated to temperature.The experimental results showed high correlation between temperature and natural frequencies: a variation of +21°C reduced the natural frequency for the 1st transverse mode of the deck by as much as 30.6% while the 1st vertical mode was reduced by 17.7% (variation of 0.029Hz/°C).The damping ratio was also measured, though a definitive correlation between its value and temperature was not identified.This change in behaviour cannot be explained by the influence of the asphalt layer alone however, as there is a high degree of uncertainty around many other components of the bridge and their interactions, such as the connections.Thus, to fully characterize the influence of each component with changing temperature, further experimental tests would have to be performed, or simpler structures with fewer connections should be considered.In designing a new structure, considering the asphalt layer as an added mass is a straightforward way to treat this material at the most critical condition (i.e. no contribution to stiffness). This strategy lead to sufficiently similar results between the computational model and the experimental results at warm temperatures.The asphalt stiffness could perhaps be considered for the 1st transverse mode of the deck, since it is in this mode that the asphalt layer plays its largest contribution.
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AVENTO, NAMI. "Independent Living in Age-Friendly Cities: Study on Dyads of Elderly Pedestrians Walking Dynamics." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2015. http://hdl.handle.net/10281/96080.
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The present thesis has, as one of its main goals, the objective to introduce the phenomenon of Ageing Society, particularly focusing on the theme of elderly population mobility in urban environment. The originality of this thesis comes from the study of elderly dyads walking dynamics in urban settings and senior citizens' perception about the neighbourhood they live in, in terms of safety and walkable conditions. The final purpose is to demonstrate, through the analysis of institutional and scientific literature, with the help of qualitative and quantitative data collection tools, how the quality of life in older years is related to the maintenance of physical and social activities outdoor, and to infrastructure and services supporting walking mobility.
After the introduction to the theme Ageing Society (Chapter 1), the first part of the thesis (Chapters 2-3-4) discusses the importance of the concept of Independent Living as a new lifestyle for senior persons, and investigates the meaning of Walkability, the measure of walking condition, and of living conditions in general, in a definite area. These concepts can be associated to the word Age-Friendly City, which not only refers to a city attentive to citizen's needs but to every age, a city that is inclusive and aware of the wellbeing of its inhabitants. Moreover, we cannot ignore the important role that technology plays in elderly assistance and to the improvement of the quality of life. In particular, nowadays technology can make domestic living more comfortable, avoiding institutionalisation. Data collected through the administration of a long questionnaire "The perception of longevity", aiming at investigating the perception of the population regarding themes such as seniority and assistive technology, are presented in this section. Data indicates that older persons are perceived as autonomous in their daily activities and full of resources, confirming the necessity to promote an active and independent lifestyle through an increased social participation and the preservation of interpersonal relationships, also with the use of new technological solutions. The second part of the dissertation introduces the definition of "dyad of pedestrian" and an overview of the literature having as objectives pedestrian characteristics in dynamic contexts, in particular: interpersonal distance during locomotion, patterns of small groups in a crowd, elderly pedestrians exposed to environmental complexity (Chapters 5-6). The third part of the thesis (Chapters 7-8) presents two study cases: in vivo observation in Galleria Vittorio Emanuele II in Milan for data collection and analysis concerning pedestrian dynamics, and the administration of short questionnaires in Via Padova in Milan, with the aim of acquiring the experience of elderly people living in the neighbourhood and the conditions of walkability and safety. The results highlight important insights related to the walking behaviour of older people in terms of speed, direction, trajectory, cohesion and about dyads of pedestrians in a complex environment such as a non-signalised street crossing. Conclusion, future works and bibliography constitute the closing part of the thesis (Chapters 9-10).
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Shahabpoor, Erfan. "Dynamic interaction of walking humans with pedestrian structures in vertical direction experimentally based probabilistic modelling." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/7241/.
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There is a lack of credible and usable knowledge, specifically related to human-structure interaction in the vertical direction despite of its importance and potentially huge economic impact. The research presented in this thesis addresses this problem via a systematic combined experimental and analytical study of the effects of people on dynamic properties of vibrating structures they excite by walking. Series of extensive frequency response function based modal tests were performed on a full-scale test structure with more than one hundred test subjects walking in different loading scenarios. The experimental results were then used to identify the parameters of a single-degree-of-freedom (SDOF) mass-spring-damper (MSD) model of a walking human. Four different approaches, including agent-based modelling, were used to simulate measured scenarios of multi-pedestrian traffic. It was found that normal distributions with μ=2.864 Hz and σ= 0.191 Hz, and μ=0.295 and σ= 0.023 can describe the natural frequency and damping ratio of the SDOF MSD model of a walking human, respectively, when total mass of the human body is assumed as the mass of the SDOF system. A new vibration serviceability assessment method was proposed that takes into account not only the variability of the human body MSD parameters and the forcing function but also their interaction with the structure. Application of this novel method on two full-scale structures under walking traffic load verified its excellent performance yielding a maximum 10% error in estimating the level of structural response compared to 200-500% error margins when key design guidelines currently used around the world were employed. This method is versatile and, being easy to apply in practice, has the potential to replace the existing methods for simulating single and multi-pedestrian traffic on footbridges and floors.
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Gu, Yecheng [Verfasser], and Jörg [Akademischer Betreuer] Siekmann. "Intelligent tutoring in virtual reality for highly dynamic pedestrian safety training / Yecheng Gu ; Betreuer: Jörg Siekmann." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2019. http://d-nb.info/1188612050/34.
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Gu, Yecheng Verfasser], and Jörg H. [Akademischer Betreuer] [Siekmann. "Intelligent tutoring in virtual reality for highly dynamic pedestrian safety training / Yecheng Gu ; Betreuer: Jörg Siekmann." Saarbrücken : Saarländische Universitäts- und Landesbibliothek, 2019. http://d-nb.info/1188612050/34.
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Qiu, Fasheng. "A Framework for Group Modeling in Agent-Based Pedestrian Crowd Simulations." Digital Archive @ GSU, 2010. http://digitalarchive.gsu.edu/cs_diss/56.
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Pedestrian crowd simulation explores crowd behaviors in virtual environments. It is extensively studied in many areas, such as safety and civil engineering, transportation, social science, entertainment industry and so on. As a common phenomenon in pedestrian crowds, grouping can play important roles in crowd behaviors. To achieve more realistic simulations, it is important to support group modeling in crowd behaviors. Nevertheless, group modeling is still an open and challenging problem. The influence of groups on the dynamics of crowd movement has not been incorporated into most existing crowd models because of the complexity nature of social groups. This research develops a framework for group modeling in agent-based pedestrian crowd simulations. The framework includes multiple layers that support a systematic approach for modeling social groups in pedestrian crowd simulations. These layers include a simulation engine layer that provides efficient simulation engines to simulate the crowd model; a behavior-based agent modeling layers that supports developing agent models using the developed BehaviorSim simulation software; a group modeling layer that provides a well-defined way to model inter-group relationships and intra-group connections among pedestrian agents in a crowd; and finally a context modeling layer that allows users to incorporate various social and psychological models into the study of social groups in pedestrian crowd. Each layer utilizes the layer below it to fulfill its functionality, and together these layers provide an integrated framework for supporting group modeling in pedestrian crowd simulations. To our knowledge this work is the first one to focus on a systematic group modeling approach for pedestrian crowd simulations. This systematic modeling approach allows users to create social group simulation models in a well-defined way for studying the effect of social and psychological factors on crowd’s grouping behavior. To demonstrate the capability of the group modeling framework, we developed an application of dynamic grouping for pedestrian crowd simulations.
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Ozerkan, Taner. "Instrumented Monitoring And Dynamic Testing Of Metu Cable Stayed Pedestrian Bridge And Comparisons Against The Analytical Model Simulations." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606335/index.pdf.
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This study includes structural instrumentation and monitoring of a 48.5 meters long cable-stayed pedestrian bridge located on EskiSehir road near METU campus. The objectives of the study are (1) to monitor the bridge responses during erection and operation stages so that the strain changes are determined during important events such as transportation, lifting, cabling, mid-support removal, slab concrete pouring and tile placement, (2) to determine existing cable forces using vibration frequencies, and (3) comparison of the experimental and analytical results for model updating.
A total of 10 vibrating wire type strain gages were used for strain readings in steel members. The readings are taken at various stages of construction at every 10 to 30 minutes intervals. The bridge responses were monitored about three months and large strain changes in the order of 300 to 500 micro-strain were recorded during important events (e.g., transportation, lifting, cabling, mid-support removal, deck cover placement).
The deck and tower natural vibration frequency measurements are conducted in two main directions. Two different FE models are constructed using two levels of complexity. FEM analysis results are compared against measured natural frequencies of the bridge and tower.
Simplistic analytical model is modified to include temporary support removal in order to perform staged construction simulation and investigate cable force variations. Actual cable tensile forces are obtained using measured cable natural vibration frequencies. The cable frequencies are measured using a CR10X data logger and a PCB 393C accelerometer. Existing cable forces are compared against analytical simulations and symmetrically placed cables
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Hanzlík, Tomáš. "Analýza dynamického chování štíhlých konstrukcí a návrh zařízení na omezení vibrací." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-392278.
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Thesis deals with the modeling of pedestrian excitation of structures and obtaining the corresponding dynamic response of the structure. The trend of modern slender structures places more emphasis on the accuracy of modeling pedestrian dynamic excitation, which is difficult because of the intelligent behavior of pedestrians and the biological nature of the modeled pedestrian. First part of the thesis deals with traditional models of pedestrian excitation, based on application of pedestrian ground force to the model of construction. Models are explored on a model of slender footbridge for many different excitation variants in order to explore the specifics of the force excitation application and the structure response calculation. In second part of the thesis biomechanical pedestrian models are developed, including inertial forces, to calculate the pedestrian interaction with the structure. Parametric studies carried out on simplified structural models research the influence of design parameters of biomechanical models on dynamic response. The aim is to obtain a more accurate model of the pedestrian-construction system for refinement of the design of structures. The design of a tuned mass dampers for the reduction of pedestrian induced vibrations is also explored. Tuned mass dampers are devoted to parametric studies that deal with the influence of design parameters of the damper on the efficiency and design requirements of the device. The aim is to explore the design parameters and their influence on the efficient and economical design of the device. In the thesis were developed two biomechanical models, a simple biomechanical model with one vertical degree of freedom and a bipedal model of a human walking. Models have proven a certain degree of interaction when exciting light footbridges by one pedestrian. Bipedal model then also brought a partial insight into the mechanics of walking and the causes of pedestrian contact forces.
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Sîrbu, Adela-Maria. "Dynamic machine learning for supervised and unsupervised classification." Thesis, Rouen, INSA, 2016. http://www.theses.fr/2016ISAM0002/document.
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La direction de recherche que nous abordons dans la thèse est l'application des modèles dynamiques d'apprentissage automatique pour résoudre les problèmes de classification supervisée et non supervisée. Les problèmes particuliers que nous avons décidé d'aborder dans la thèse sont la reconnaissance des piétons (un problème de classification supervisée) et le groupement des données d'expression génétique (un problème de classification non supervisée). Les problèmes abordés sont représentatifs pour les deux principaux types de classification et sont très difficiles, ayant une grande importance dans la vie réelle. La première direction de recherche que nous abordons dans le domaine de la classification non supervisée dynamique est le problème de la classification dynamique des données d'expression génétique. L'expression génétique représente le processus par lequel l'information d'un gène est convertie en produits de gènes fonctionnels : des protéines ou des ARN ayant différents rôles dans la vie d'une cellule. La technologie des micro-réseaux moderne est aujourd'hui utilisée pour détecter expérimentalement les niveaux d'expression de milliers de gènes, dans des conditions différentes et au fil du temps. Une fois que les données d'expression génétique ont été recueillies, l'étape suivante consiste à analyser et à extraire des informations biologiques utiles. L'un des algorithmes les plus populaires traitant de l'analyse des données d'expression génétique est le groupement, qui consiste à diviser un certain ensemble en groupes, où les composants de chaque groupe sont semblables les uns aux autres données. Dans le cas des ensembles de données d'expression génique, chaque gène est représenté par ses valeurs d'expression (caractéristiques), à des points distincts dans le temps, dans les conditions contrôlées. Le processus de regroupement des gènes est à la base des études génomiques qui visent à analyser les fonctions des gènes car il est supposé que les gènes qui sont similaires dans leurs niveaux d'expression sont également relativement similaires en termes de fonction biologique. Le problème que nous abordons dans le sens de la recherche de classification non supervisée dynamique est le regroupement dynamique des données d'expression génique. Dans notre cas, la dynamique à long terme indique que l'ensemble de données ne sont pas statiques, mais elle est sujette à changement. Pourtant, par opposition aux approches progressives de la littérature, où l'ensemble de données est enrichie avec de nouveaux gènes (instances) au cours du processus de regroupement, nos approches abordent les cas lorsque de nouvelles fonctionnalités (niveaux d'expression pour de nouveaux points dans le temps) sont ajoutés à la gènes déjà existants dans l'ensemble de données. À notre connaissance, il n'y a pas d'approches dans la littérature qui traitent le problème de la classification dynamique des données d'expression génétique, définis comme ci-dessus. Dans ce contexte, nous avons introduit trois algorithmes de groupement dynamiques que sont capables de gérer de nouveaux niveaux d'expression génique collectés, en partant d'une partition obtenue précédente, sans la nécessité de ré-exécuter l'algorithme à partir de zéro. L'évaluation expérimentale montre que notre méthode est plus rapide et plus précis que l'application de l'algorithme de classification à partir de zéro sur la fonctionnalité étendue ensemble de donnéesThe research direction we are focusing on in the thesis is applying dynamic machine learning models to salve supervised and unsupervised classification problems. We are living in a dynamic environment, where data is continuously changing and the need to obtain a fast and accurate solution to our problems has become a real necessity. The particular problems that we have decided te approach in the thesis are pedestrian recognition (a supervised classification problem) and clustering of gene expression data (an unsupervised classification. problem). The approached problems are representative for the two main types of classification and are very challenging, having a great importance in real life.The first research direction that we approach in the field of dynamic unsupervised classification is the problem of dynamic clustering of gene expression data. Gene expression represents the process by which the information from a gene is converted into functional gene products: proteins or RNA having different roles in the life of a cell. Modern microarray technology is nowadays used to experimentally detect the levels of expressions of thousand of genes, across different conditions and over time. Once the gene expression data has been gathered, the next step is to analyze it and extract useful biological information. One of the most popular algorithms dealing with the analysis of gene expression data is clustering, which involves partitioning a certain data set in groups, where the components of each group are similar to each other. In the case of gene expression data sets, each gene is represented by its expression values (features), at distinct points in time, under the monitored conditions. The process of gene clustering is at the foundation of genomic studies that aim to analyze the functions of genes because it is assumed that genes that are similar in their expression levels are also relatively similar in terms of biological function.The problem that we address within the dynamic unsupervised classification research direction is the dynamic clustering of gene expression data. In our case, the term dynamic indicates that the data set is not static, but it is subject to change. Still, as opposed to the incremental approaches from the literature, where the data set is enriched with new genes (instances) during the clustering process, our approaches tackle the cases when new features (expression levels for new points in time) are added to the genes already existing in the data set. To our best knowledge, there are no approaches in the literature that deal with the problem of dynamic clustering of gene expression data, defined as above. In this context we introduced three dynamic clustering algorithms which are able to handle new collected gene expression levels, by starting from a previous obtained partition, without the need to re-run the algorithm from scratch. Experimental evaluation shows that our method is faster and more accurate than applying the clustering algorithm from scratch on the feature extended data set
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Marzi, Tommaso. "Dynamical models for pedestrian dynamics using data from pedestrian flow sensors." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21219/.
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The purpose of this thesis is to give a contribution in a wider project regarding the development of new tools for the governance of tourist flows in Venice. Because of the virus COVID-19, this topic has increased in interest, since it can be used both to look for possible solutions to make public places safer and to study the spread of the virus itself.
Once the testing of the sensors that provide the data on mobility is carried out, a macroscopic approach to the pedestrian dynamics based on the Fundamental Diagram is proposed: scenarios with different geometries as streets, crossroads or bridges are compared, focusing in particular on representative parameters of the model.
In the last part, a microscopic approach to pedestrian mobility is presented: a simulation model is calibrated on the basis of the available data, in order to define whether it can actually reproduce the behaviour of a crowd.
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Huang, Ming-Hui. "Dynamic characteristics of slender suspension footbridges." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16450/1/Ming-Hui_Huang_Thesis.pdf.
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Due to the emergence of new materials and advanced engineering technology, slender footbridges are increasingly becoming popular to satisfy the modern transportation needs and the aesthetical requirements of society. These structures however are always "lively" with low stiffness, low mass, low damping and low natural frequencies. As a consequence, they are prone to vibration induced by human activities and can suffer severe vibration serviceability problems, particularly in the lateral direction. This phenomenon has been evidenced by the excessive lateral vibration of many footbridges worldwide such as the Millennium Bridge in London and the T-Bridge in Japan. Unfortunately, present bridge design codes worldwide do not provide sufficient guidelines and information to address such vibrations problems and to ensure safety and serviceability due to the lack of knowledge on the dynamic performance of such slender vibration sensitive bridge structures.
A conceptual study has been carried out to comprehensively investigate the dynamic characteristics of slender suspension footbridges under human-induced dynamic loads and a footbridge model in full size with pre-tensioned reverse profiled cables in the vertical and horizontal planes has been proposed for this purpose. A similar physical suspension bridge model was designed and constructed in the laboratory, and experimental testings have been carried out to calibrate the computer simulations. The synchronous excitation induced by walking has been modelled as crowd walking dynamic loads which consist of dynamic vertical force, dynamic lateral force and static vertical force. The dynamic behaviour under synchronous excitation is simulated by resonant vibration at the pacing rate which coincides with a natural frequency of the footbridge structure. Two structural analysis software packages, Microstran and SAP2000 have been employed in the extensive numerical analysis.
Research results show that the structural stiffness and vibration properties of suspension footbridges with pre-tensioned reverse profiled cables can be adjusted by choosing different structural parameters such as cable sag, cable section and pretensions in the reverse profiled cables. Slender suspension footbridges always have four main kinds of vibration modes: lateral, torsional, vertical and longitudinal modes. The lateral and torsional modes are often combined together and become two kinds of coupled modes: coupled lateral-torsional modes and coupled torsionallateral modes. Such kind of slender footbridges also have different dynamic performance in the lateral and vertical directions, and damping has only a small effect on the lateral vibration but significant effect on the vertical one.
The fundamental coupled lateral-torsional mode and vertical mode are easily excited when crowd walking dynamic loads are distributed on full bridge deck. When the crowd walking dynamic loads are distributed eccentrically on half width of the deck, the fundamental coupled torsional-lateral mode can be excited and large lateral deflection can be induced. Higher order vertical modes and coupled lateral-torsional modes can also be excited by groups of walking pedestrians under certain conditions.
It is found that the coupling coefficient introduced in this thesis to describe the coupling of a coupled mode, is an important factor which has significant effect on the lateral dynamic performance of slender suspension footbridges. The coupling coefficient, however, is influenced by many structural parameters such as cable configuration, cable section, cable sag, bridge span and pre-tensions, etc. In general, a large dynamic amplification factor is expected when the fundamental mode of a footbridge structure is the coupled lateral-torsional mode with a small coupling coefficient.
The research findings of this thesis are useful in understanding the complex dynamic behaviour of slender and vibration sensitive suspension footbridges under humaninduced dynamic loads. They are also helpful in developing design guidance and techniques to improve the dynamic performance of such slender vibration sensitive footbridges and similar structures and hence to ensure their safety and serviceability.
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Huang, Ming-Hui. "Dynamic characteristics of slender suspension footbridges." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16450/.
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Due to the emergence of new materials and advanced engineering technology, slender footbridges are increasingly becoming popular to satisfy the modern transportation needs and the aesthetical requirements of society. These structures however are always "lively" with low stiffness, low mass, low damping and low natural frequencies. As a consequence, they are prone to vibration induced by human activities and can suffer severe vibration serviceability problems, particularly in the lateral direction. This phenomenon has been evidenced by the excessive lateral vibration of many footbridges worldwide such as the Millennium Bridge in London and the T-Bridge in Japan. Unfortunately, present bridge design codes worldwide do not provide sufficient guidelines and information to address such vibrations problems and to ensure safety and serviceability due to the lack of knowledge on the dynamic performance of such slender vibration sensitive bridge structures. A conceptual study has been carried out to comprehensively investigate the dynamic characteristics of slender suspension footbridges under human-induced dynamic loads and a footbridge model in full size with pre-tensioned reverse profiled cables in the vertical and horizontal planes has been proposed for this purpose. A similar physical suspension bridge model was designed and constructed in the laboratory, and experimental testings have been carried out to calibrate the computer simulations. The synchronous excitation induced by walking has been modelled as crowd walking dynamic loads which consist of dynamic vertical force, dynamic lateral force and static vertical force. The dynamic behaviour under synchronous excitation is simulated by resonant vibration at the pacing rate which coincides with a natural frequency of the footbridge structure. Two structural analysis software packages, Microstran and SAP2000 have been employed in the extensive numerical analysis. Research results show that the structural stiffness and vibration properties of suspension footbridges with pre-tensioned reverse profiled cables can be adjusted by choosing different structural parameters such as cable sag, cable section and pretensions in the reverse profiled cables. Slender suspension footbridges always have four main kinds of vibration modes: lateral, torsional, vertical and longitudinal modes. The lateral and torsional modes are often combined together and become two kinds of coupled modes: coupled lateral-torsional modes and coupled torsionallateral modes. Such kind of slender footbridges also have different dynamic performance in the lateral and vertical directions, and damping has only a small effect on the lateral vibration but significant effect on the vertical one. The fundamental coupled lateral-torsional mode and vertical mode are easily excited when crowd walking dynamic loads are distributed on full bridge deck. When the crowd walking dynamic loads are distributed eccentrically on half width of the deck, the fundamental coupled torsional-lateral mode can be excited and large lateral deflection can be induced. Higher order vertical modes and coupled lateral-torsional modes can also be excited by groups of walking pedestrians under certain conditions. It is found that the coupling coefficient introduced in this thesis to describe the coupling of a coupled mode, is an important factor which has significant effect on the lateral dynamic performance of slender suspension footbridges. The coupling coefficient, however, is influenced by many structural parameters such as cable configuration, cable section, cable sag, bridge span and pre-tensions, etc. In general, a large dynamic amplification factor is expected when the fundamental mode of a footbridge structure is the coupled lateral-torsional mode with a small coupling coefficient. The research findings of this thesis are useful in understanding the complex dynamic behaviour of slender and vibration sensitive suspension footbridges under humaninduced dynamic loads. They are also helpful in developing design guidance and techniques to improve the dynamic performance of such slender vibration sensitive footbridges and similar structures and hence to ensure their safety and serviceability.
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Thufvesson, Eric, and Daniel Andersson. "Dynamic Analysis of the Skyway Bridge : Assessment and Application of Design Guidelines." Thesis, KTH, Bro- och stålbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208685.
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In recent years the design of pedestrian bridges has become more slender. As a result the bridges has lower natural frequencies and are more prone to excessive vibrations when subjected to dynamic loads induced by pedestrians. Akademiska Hus are building such a bridge at Nya Karolinska Solna where the bridge will span over Solnavägenconnecting the hospital building, U2, and the research facility BioMedicum. Due to practical reasons, it is not possible to connect one of the bridge ends mechanicallyto the building which increases the risk for lateral modes in the sensitivefrequency range of 0-2.5 Hz. The increased risk of lateral modes of vibrations within the sensitive frequency range as well uncertainties when determining the dynamic response led to this thesis. This thesis covers a frequency analysis of the previously mention bridge and an evaluation of the dynamic response under pedestrian loading by implementation of several design guidelines. A literature review was conducted with the aim of giving a deeper knowledge of human induced vibrations and the relevant guidelines for modelling of pedestrian loading. Furthermore, a parametric study was conducted for parameters which might be prone to uncertainties in data. The investigated parameters were the Young’s modulus for concrete and the surrounding fill materialas well as the stiffness of the connection to BioMedicum. The parametric study yielded a frequency range of 2.20-2.93 Hz for the first lateral mode and 5.96-6.67 Hz for the first vertical mode of vibration. By including nonstructural mass the lower limit for the frequencies were lowered to 2.05 and 5.59 Hzin the first lateral and vertical mode respectively. The parametric study also showed that the largest impact on the natural frequencies were obtained by manipulating the parameters for the supports, both for BioMedicum and the substructure. The implementation of the guidelines resulted in a lateral acceleration between 0.05 and0.599 m/s2. No evaluation was conducted for the dynamic response in the vertical direction due to a natural frequency of 5.59 Hz, which is higher than the evaluation criteria stated in Eurocode 0. The results showed that the design of the Skyway bridge is dynamically sound with regard to pedestrian loading and no remedial actions are necessary.
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Silva, Petrúcio Barrozo da. "Transporte de partículas em sistemas mesoscópicos." reponame:Repositório Institucional da UFC, 2009. http://www.repositorio.ufc.br/handle/riufc/12894.
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SILVA, Petrúcio Barrozo da. Transporte de partículas em sistemas mesoscópicos. 2009. 140 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2009.Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-06-18T19:09:21Z No. of bitstreams: 1 2009_tese_pbsilva.pdf: 5386527 bytes, checksum: 013c727ad138df44286d71defdc66882 (MD5)
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In this work we investigate the transport properties of particles in mesoscopic systems. In the first part, we use the model originally proposed by Zapperi et al. (Phys. Rev. Lett. 86, 3622 (2001)) to describe the steady-state transport of overdamped particles in the presence of an obstacle and confined to a channel with width of the order of the characteristic size of the system. With this model, we obtain a non-linear first-order differential equation, whose solution in 1D is capable to describe the behavior of the particle density along a 2D channel for different particle systems (e.g., superconducting vortices, colloids and pedestrians, all simulated with molecular dynamics) and obstacle types (e.g, one energy barrier, a channel constriction and a network of pinning centers). We observe that such a model can be used to represent the flow of any system of overdamped particles, as long as the interactions between them can reach a distance greater than only the first neighbors. In the second part of this work, we investigate the flow of interacting particles (not necessarily overdamped) confined to a channel of asymmetrical walls. Here the main objective is to describe through molecular dynamics techniques both the flow of pedestrians as well as the transport of superconducting vortices through irregular channels. In both cases, we observe that the asymmetry of the confining walls can induce a preferential direction to the flow. In the case of pedestrians, our results indicate that, when two groups of people move in opposite directions in a ratcheted type of corridor, this induced order is also responsible for flow maximization. This order can be destroyed, however, when we change the total number of particles in the system, their target speed, the amplitude of the external added noise or the degree of the asymmetry of the channel. We also observe that the order-disorder transitions in this system are usually followed by metastability and hysteresis cycles. In the case of superconducting vortices, multiple depinning transitions are observed when there is a small comensurability field between the number of ratchets in the channel and the number of particles (vortices) in the system.
Neste trabalho, estudamos as propriedades do transporte de partículas em sistemas mesoscópicos. Na primeira parte, usamos o modelo proposto anteriormente por Zapperi et al. (Phys. Rev. Lett. 86, 3622 (2001)) para descrever o transporte de partículas superamortecidas e interagentes no estado estacionário, na presença de um obstáculo para o fluxo, e confinadas em um canal com largura da ordem do comprimento característico do sistema. Com este modelo, obtivemos uma equação diferencial de primeira ordem não-linear, cuja solução em 1D é capaz de descrever a densidade ao longo de um canal 2D para diferentes sistemas de partículas (e.g., vórtices em supercondutores, colóides e pedestres, todos simulados por dinâmica molecular) e diferentes tipos de obstáculos (e.g., uma barreira de energia, um canal com uma constrição e uma rede de pinos no centro do canal). Observamos que este modelo pode ser usado para descrever o escoamento de qualquer sistema de partículas superamortecido, desde que as interações entre elas possam alcançar distâncias maiores que os primeiros vizinhos. Na segunda parte deste trabalho, estudamos o escoamento de partículas interagentes (não necessariamente superamortecidas) confinadas por paredes assimétricas. Aqui o objetivo é descrever a dinâmica de pedestres e a dinâmica de vórtices em supercondutores. Em ambos os sistemas, as paredes assimétricas são responsáveis pela introdução de um sentido preferencial para o fluxo. No caso da dinâmica de pedestres, estudamos as propriedades do sistema quando os pedestres andam em sentidos opostos. Verificamos que este confinamento induz uma ordem responsável pela maximização do escoamento. Esta ordem pode ser destruída quando variamos a densidade, a velocidade, a razão entre a largura do canal e a sua rugosidade, o ruído externo e a assimetria do canal. Verificamos também que as transições de ordem-desordem neste sistema são acompanhadas de metaestabilidades e ciclos de histerese. No caso de vórtices em supercondutores, verificamos que, para pequenos campos de comensurabilidade entre o número de "catracas" e o número de vórtices, o sistema apresenta múltiplas transições de depinamento.
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Prokš, Tomáš. "Dynamická analýza mostních konstrukcí." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265612.
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The diploma thesis deals with dynamic analysis of cable-stayed steel pedestrian footbridge. The dynamic response of pedestrian-induced vibration was studied. The response of structure exeeded standard acceptance limit. Due to the effect of installed Tuned Mass Damper was studied. Motion equations of single and two degree of freedom model were solved in program MATLAB and the results were compared with numeric model in ANSYS.
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Cabrero, Daniel Beatriz. "Automating crowd simulation: from parameter tuning to dynamic context-to-policy adaptation." Doctoral thesis, Universitat Pompeu Fabra, 2022. http://hdl.handle.net/10803/673251.
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Computer-generated crowds are becoming more and more frequent in films, video games and safety assessment applications. Many crowd simulation algorithms exist to address the needs of this diverse range of industries. Even though the underlying principles are similar, there are large differences between the resulting synthetic trajectories. Each algorithm has strengths and weaknesses that need to be weighted, and appropriate parameter values for them must be selected as well. These are not easy tasks and Machine Learning algorithms are often used to guide these decisions. In this work we study three of these tasks: parameter tuning, trajectory evaluation, and character policy selection and adaptation. Our results show the usefulness of the proposed methods to evaluate previously unseen synthetic trajectories to find appropriate parameter values for the algorithms without directly relying on real data. Moreover, by classifying the context of characters, we propose a policy adaptation strategy to improve crowd simulations.Les multituds simulades per ordinador són cada cop més habituals en cinema, vídeo jocs i en aplicacions relacionades amb la seguretat. Existeixen molts algoritmes per simular multituds per adreçar tal varietat d’indústries. Tot i que els principis subjacents són similars, hi ha diferències entre les simulacions resultants. Cada algoritme té avantatges i inconvenients que s’han de valorar, i, a més a més, cal trobar valors pels seus paràmetres. Aquestes no són tasques senzilles i, sovint, es fan servir algoritmes d’aprenentatge automàtic per guiar aquestes decisions. Estudiem tres d’aquestes tasques: donar valor als paràmetres, avaluar trajectòries, i adaptar les polítiques. Els resultats demostren la utilitat dels mètodes proposats per avaluar trajectòries noves per tal de trobar valors apropiats pels paràmetres dels algorismes sense fer servir dades reals directament. A més a més, proposem una estratègia per adaptar la política de cada agent a través del reconeixement del context, millorant les simulacions.
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Almeida, Jorge Manuel Soares de. "Active tracking of dynamic multivariate agents using vectorial range data." Doctoral thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/16988.
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Doutoramento em Engenharia MecânicaO objeto principal da presente tese é o estudo de sistemas avançados de segurança, no âmbito da segurança automóvel, baseando-se na previsão de movimentos e ações dos agentes externos. Esta tese propõe tratar os agentes como entidades dinâmicas, com motivações e constrangimentos próprios. Apresenta-se, para tal, novas técnicas de seguimento dos referidos agentes levando em linha de conta as suas especificidades. Em decorrência, estuda-se dedicadamente dois tipos de agentes: os veículos automóveis e os peões. Quanto aos veículos automóveis, propõe-se melhorar a capacidade de previsão de movimentos recorrendo a modelos avançados que representam corretamente os constrangimentos presentes nos veículos. Assim, foram desenvolvidos algoritmos avançados de seguimento de agentes com recurso a modelos de movimento não holonómicos. Estes algoritmos fazem uso de dados vectoriais de distância fornecidos por sensores de distância laser. Para os peões, devido à sua complexidade (designadamente a ausência de constrangimentos de movimentos) propõe-se que a análise da sua linguagem corporal permita detetar atempadamente possíveis intenções de movimentos. Assim, foram desenvolvidos algoritmos de perceção de pose de peões adaptados ao campo da segurança automóvel com recurso a uso de dados de distâncias 3D obtidos com uma câmara stereo. De notar que os diversos algoritmos foram testados em experiências realizadas em ambiente real.
The main topic of this thesis is the study of advanced safety systems, in the field of automotive safety, based on the prediction of the movement and actions of external agents. This thesis proposes to treat the agents as dynamic entities with their own motivations as constraints. As so, new target tracking techniques are proposed taking into account the targets’ specificities. Therefore, two different types of agents are dedicatedly studied: automobile vehicles and pedestrians. For the automobile vehicles, a technique to improve motion prediction by the use of advanced motion models is proposed, these models will correctly represent the constrains that exist in this kind of vehicle. With this goal, advanced target tracking algorithms coupled with nonholonomic motion models were developed. These algorithms make use of vectorial range data supplied by laser range sensors. Concerning the pedestrians, due to the problem complexity (mainly due to the lack of any specific motion constraint), it is proposed that the analysis of the pedestrians body language will allow to detected early the pedestrian intentions and movements. As so, pedestrian pose estimation algorithms specially adapted to the field of automotive safety were developed; these algorithms use 3D point cloud data obtained with a stereo camera. The various algorithms were tested in experiments conducted in real conditions.
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Tačner, Jan. "Analýza působení větru na stavební konstrukci." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227314.
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Diploma thesis deals with static and dynamic analyses of a slender bridge structure behavior. The footbridge structure model was created in ANSYS 14.5 programing system. Static and a modal analyses were made afterwards and according to these analyses dynamic wind load and dynamic pedestrian load were applied. Wind load was applied as option of deck without a handrail and as option of deck with fully airtight handrail. Pedestrians were perceived as group of pedestrians and as a sparse crowd. Both applied loads were solved by harmonic analyses. Results of these analyses are resonance curves and tables of accleration.
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Debona, Gilvan Lunz. "Modelagem do comportamento dinâmico de passarelas tubulares em aço e mistas (aço-concreto)." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3419.
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Fundação de Amparo à Pesquisa do Estado do Rio de JaneiroA experiência dos engenheiros estruturais e os conhecimentos adquiridos pelo uso de materiais e novas tecnologias, têm ocasionado estruturas de aço e mistas (aço-concreto) de passarelas cada vez mais ousadas. Este fato tem gerado estruturas de passarelas esbeltas, e consequentemente, alterando os seus estados de limite de serviço e último associados ao seu projeto. Uma consequência direta desta tendência de projeto é o aumento considerável das vibrações das estruturas. Portanto, a presente investigação foi realizada com base em um modelo de carregamento mais realista, desenvolvido para incorporar os efeitos dinâmicos induzidos pela caminhada de pessoas. O modelo de carregamento considera a subida e a descida da massa efetiva do corpo em cada passo. A posição da carga dinâmica também foi alterada de acordo com a posição do pedestre sobre a estrutura e a função do tempo gerada, possui uma variação espacial e temporal. O efeito do calcanhar do pedestre também foi incorporado na análise. O modelo estrutural investigado baseia-se em uma passarela tubular (aço-concreto), medindo 82,5m. A estrutura é composta por três vãos (32,5 m, 20,0 m e 17,5 m, respectivamente) e dois balanços (7,5 m e 5,0 m, respectivamente). O sistema estrutural é constituído por perfis de aço tubular e uma laje de concreto, e é atualmente utilizada para travessia de pedestres. Esta investigação é realizada com base em resultados experimentais, relacionando a resposta dinâmica da passarela com as obtidas via modelos de elementos finitos. O modelo computacional proposto adota as técnicas de refinamento de malha, usualmente presente em simulações pelo método de elementos finitos. O modelo de elementos finitos foi desenvolvido e validado com resultados experimentais. Este modelo de passarela tubular permitiu uma avaliação dinâmica completa, investigando especialmente ao conforto humano e seus limites de utilização associados à vibração. A resposta dinâmica do sistema, em termos de acelerações de pico, foi obtida e comparada com os valores limites propostos por diversos autores e padrões de projeto. As acelerações de pico encontradas na presente análise indicou que a passarela tubular investigada apresentou problemas relacionados com o conforto humano. Por isso, foi detectado que este tipo de estrutura pode atingir níveis de vibrações excessivas que podem comprometer o conforto do usuário na passarela e especialmente a sua segurança.
The structural engineers experience and knowledge allied by the use newly developed materials and technologies have produced steel and composite (steel-concrete) footbridges with daring structures. This fact have generated very slender structural footbridges and consequently changed the serviceability and ultimate limit states associated to their design. A direct consequence of this design trend is a considerable increase of structural vibrations. Therefore, the present investigation was carried out based on a more realistic load model developed to incorporate the dynamic effects induced by people walking. The load model considered the ascent and descending movement of the human body effective mass at each step. The position of the dynamic load was also changed according to the individual position and the generated time function, having a space and time description. The effect of the human heel was also incorporated in the analysis. The investigated structural model was based on a tubular composite (steel-concrete) footbridge, spanning 82.5 m. The structure is composed by three spans (32.5 m, 17.5 m and 20.0 m, respectively) and two overhangs (7.5 m and 5.0 m, respectively). The structural system is constituted by tubular steel sections and a concrete slab and is currently used for pedestrian crossing. This investigation is carried out based on correlations between the experimental results related to the footbridge dynamic response and those obtained with finite element models. The proposed computational model adopted the usual mesh refinement techniques present in finite element method simulations. The finite element model has been developed and validated with the experimental results. This model enabled a complete dynamic evaluation of the investigated tubular footbridge especially in terms of human comfort and its associated vibration serviceability limit states. The system dynamic response, in terms of peak accelerations, was obtained and compared to the limiting values proposed by several authors and design standards. The peak accelerations found in the present analysis indicated that the investigated tubular footbridge presented problems related with human comfort. Hence it was detected that this type of structure can reach high vibration levels that can compromise the footbridge users comfort and especially its safety.
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Cramer, Jay Alan 1957. "APPLICATION OF POLYHEDRAL DYNAMICS TO PEDESTRIAN ACCIDENTS (TRANSPORTATION)." Thesis, The University of Arizona, 1986. http://hdl.handle.net/10150/277115.
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Sourtzinos, Panagiotis. "Vision-based analysis and simulation of pedestrian dynamics." Thesis, Kingston University, 2016. http://eprints.kingston.ac.uk/35839/.
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The aim of this thesis is to examine the applicability of computer vision to analyze pedestrian and crowd characteristics, and how pedestrain simulation for shopping environments can be driven from the visual perception of the simulated pedestrians. More specifically, two frameworks for pedestrian speed profile estimation are designed and implemented. The first address the problem of speed estimation for people moving parallel to the image plane on a flat surface, while the other tries to estimate the speed of people walking on stairs moving while their trajectories and being perpendicular on the image plane. Both approaches aim to localise the foot of the pedestrains, and by identifying their steps measure their speed. Except from measuring the speed of pedestrains, a crowd counting system using Convolutional Neural Networks is created by exploiting the background spatial persistence of a whole image in the temporal domain, and furthermore by fusing consecutive temporal counting information in the systme further refines its estimates. Finally a novel memory-free cognitive framework for pedestrian shopping behaviour is presented where the simulated pedestrians use as route choice model their visual perception. Agents moving in an environment and equipped with an activity agenda. use their vision to select not only their root choices but also the shops that they visit.
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Costa, Giancarlo. "HSI effects on pedestrian bridges." Thesis, KTH, Bro- och stålbyggnad, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-301243.
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The study on Human Structure Interaction (HSI) effects represent a new research field in the design of pedestrian bridges. The presence of pedestrians on the structure affects the dynamic properties of the bridge, and these changes may be quantified in order to design pedestrian bridges in a more efficient way. The Dynamic Amplification Factor (DAF) curve shifts downward and towards the left when increasing number of pedestrians. The thesis, which is strictly connected to a journal paper to be submitted in 2021, includes a new formulation of the dynamic response through the DAF curves and an experimental campaign to verify the shift. A HSI model, based on Caprani continuous formulation, was created on MATLAB.To perform the experimental campaign, the Folke Bernadotte Bridge in Stockholm was chosen. The dynamic response due to a hammer test, was registered without pedestrians and with 35 pedestrians on the bridge. The dynamic properties of the bridge, such as natural frequencies, damping, mode-shapes, Frequency Response Function (FRF) are estimated in both cases. A Finite Element Model (FEM) is built on Abaqus, natural frequencies and mode-shapes are compared. Moreover, a running test is performed on the bridge and the single pedestrian loading is modelled as a moving harmonic. This test brings different values of stiffness and damping for the pedestrian to be compared to the values assumed in the HSI model for standing pedestrians.A quantification of the variation of the bridge properties due to Human structure interaction may lead to a new way to design pedestrian bridges considering pedestrians not only as loading sources of the structural system but also as dynamic vibration adsorbers (DVA).
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Adler, Filip. "Mostní konstrukce podporovaná kabely." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-265663.
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The subject of this master thesis is to design a pedestrian bridge supported by cables. There are three variants of studies created for this case and for most suitable one, all documentations were produced. The primary focus of this work is on static design solution with an output of several drawings. Static model for results from load cases included construction stages and was created in Midas Civil. Design and checks were performed by hand calculations, complemented by checks of several sections by IDEA StatiCa software. Analysis and calculations are compliant to up-to-date codes and respect the fundamentals of analysis due to limit states.
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BELLANDI, Davide. "Discrete velocity modeling of vehicular traffic and pedestrian dynamics." Doctoral thesis, Università degli studi di Ferrara, 2016. http://hdl.handle.net/11392/2403511.
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Questa tesi si concentra principalmente sullo studio di modelli alle velocità discrete che descrivono sistemi complessi, ponendo particolare attenzione ai flussi di traffico e le dinamiche pedonali. In primo luogo abbiamo studiato l’esistenza e l'unicità di soluzioni dei problemi di Cauchy relativi ai sistemi iperbolici semilineari che provengono dai modelli alle velocità discrete, e la probabilità di tali soluzioni. Poi abbiamo considerato il problema in un dominio limitato ponendo delle condizioni al bordo che garantiscono la conservazione della massa del sistema. Inoltre abbiamo studiato il comportamento asintotico delle soluzioni, in alcuni casi particolari. Abbiamo introdotto poi una discretizzazione della variabile spaziale, grazie alla quale si possono sostituire i sistemi di equazioni alle derivate parziali studiati con dei sistemi di equazioni differenziali ordinarie. Infine abbiamo studiato il comportamento asintotico dei sistemi di equazioni differenziale ordinarie dedotti, studiando le posizioni di equilibrio e la loro stabilità nel caso in cui si venga introdotta una velocità desiderata, dando infine anche esempi di applicazioni a una folla uscente da una stanza.Aim of this thesis mainly focuses on the study of discrete velocity models describing complex systems, with emphasis on traffic flow and pedestrian dynamics. We first study existence and uniqueness of solutions of the Cauchy problem related to first order semilinear hyperbolic systems which originate from discrete velocity models, and the prolongability of these solutions. Then, we consider the initial-boundary value problem under weak assumptions that just ensure the conservation of mass. Moreover, we study the long time behaviour of these solutions in some particular cases. Finally, we discretize the spatial variable, too. Thanks to this latter disctetization we can substitute the systems of PDEs with systems of ODEs. We then study global-in-time behaviour of ODEs systems, furnishing equilibrium and stability results when in the system a desired velocity is introduced, giving also examples of applications to a crowd exiting a room.
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Hibš, Daniel. "Lávka pro pěší." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2019. http://www.nusl.cz/ntk/nusl-392084.
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This diploma thesis deals with the design of a new bridge construction over a multi-lane communication. The converted road is a pedestrian and biking trail connecting significant agglomerations. Three studies were worked out in this thesis and the C variant was selected for further detailed processing. It is an unsymmetrical suspended bridge with a cast-in-place deck. In the section above the communication, the bridge is made up of prefabricated segments. Suspension of the structure is made of two sloping pylons forming a V-shape. The analysis of the construction was carried out in the MIDAS Civil program, where a complete model of construction was entered, including a subsequent estacade. The model describes the construction process and includes creep and shrinkage of the concrete. The traffic, temperature and wind loads were used. The design was assessed for the ultimate limit states and serviceability limit states. The assessment was carried out in the IDEA StatiCa program, supplemented by manual calculations. The static calculations also include assessment of the harmonic response. Subsequently, overview drawings, detailed drawings and visualizations were developed.
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Nishinari, Katsuhiro, Satoshi Kokubo, and Kazuhiro Yamamoto. "Simulation for pedestrian dynamics by real-coded cellular automata (RCA)." Elsevier, 2007. http://hdl.handle.net/2237/20045.
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Zäll, Emma. "Modelling Pedestrian-Induced Vertical Vibrations of Footbridges." Thesis, Umeå universitet, Institutionen för fysik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-101831.
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A pedestrian crowd walking on a footbridge causes the footbridge to vibrate. These vibrations become an issue of serviceability and can give rise to discomfort for the pedestrians, whereby they should, to as large extent as possible, be prevented. Currently, there is a lack of reliable models to describe a dynamic load on a footbridge, due to a walking crowd. Therefore, there is a need for such models. Lately, a great amount of research has been carried out on the subject pedestrian-induced vibrations of footbridges, though most of it with focus on lateral vibrations. Conversely, this project has been performed aiming to accurately model pedestrian-induced vertical vibrations of a general footbridge. For that purpose, starting from an existing model, a somewhat improved model, comprising three sub-model, has been developed. The sub-models are: one model of the pedestrian crowd walking along the footbridge, one model describing the load from the pedestrian footstep and one model describing the interaction between the pedestrians and the footbridge. In order to get statistically reliable results, numerous simulations of the pedestrian-induced vertical vibrations of a specific footbridge have been performed, using the developed model. Averaging the results over the simulations, we could conclude that the model gives an average error of 7 %, compared to experimental data. The measured quantity giving these results was the absolute maximum value of the acceleration at the midpoint of the footbridge. The achieved dynamical response of the footbridge is qualitatively satisfying, while the quantitative error is larger than we hoped for, whereby we conclude that further improvement of the model is needed before we are able to accurately model pedestrian-induced vertical vibrations of footbridges.När en folksamling går över en gångbro uppstår vibrationer i gångbron. Dessa vibrationer påverkar brons användbarhet och kan ge upphov till obehagskänsla hos fotgängarna, vilket gör att vibrationerna i största möjliga utsträckning bör motverkas. I nuläget saknas pålitliga modeller för att beskriva den dynamiska last en gångbro utsätts för när en folksamling går över den. Således föreligger ett behov att utveckla en sådan modell. Under de senaste decennierna har mycket forskning utförts inom området människoinducerade vibrationer i gångbroar. Dock har merparten av denna forskning berört endast laterala vibrationer. Detta projekt däremot, har genomförts med syftet att, med ett noggrant resultat, modellera människoinducerade vertikala vibrationer i en generell gångbro. För att uppnå detta har jag utgått från en befintlig modell och från den utvecklat en ny modell bestående av tre delmodeller. De tre delmodellerna är: en modell som beskriver hur folksamlingen rör sig över gångbron, en modell som beskriver den kraft det mänskliga fotsteget uträttar på gångbron och en modell som beskriver interaktionen mellan fotgängarna och gångbron. För att uppnå statistiskt tillförlitliga resultat har modellen som utvecklats i detta projekt använts för att utföra åtskilliga simuleringar av människoinducerade vertikala vibrationer i en specifik gångbro. Om vi medelvärdesbildar resultaten över simuleringarna framgår det att modellen som utvecklats ger ett resultat som avviker med 7 % från experimentellt data. Detta gäller för den maximala accelerationen vid gångbrons mittpunkt. Den resulterande dynamiska responsen ser kvalitativt sett bra ut, medan den kvantitativa avvikelsen är större än vi hoppats på. Därför drar vi slutsatsen att vidare förbättringar av modellen behövs för att den ska kunna användas till att på ett noggrant sätt modellera människoinducerade vertikala vibrationer i gångbroar.
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Čáslavová, Sandra. "Statická a dynamická analýza mostní konstrukce." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2018. http://www.nusl.cz/ntk/nusl-371895.
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The aim of this thesis is to conduct static and dynamic computations for selected bridge in the Moravian region, specificaly in the surroundings of Olomouc. All calculations will be made by selected software and verified by manual reckon. The bridge is intended for pedestrian traffic and connects left and right side of the river underneath.
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Peña, Williams Dias Lozada. "Modelagem do caminhar humano e avaliação de conforto humano de passarelas de pedestres." Universidade do Estado do Rio de Janeiro, 2015. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=9073.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorCom o passar dos anos a engenharia estrutural passou a lidar com a exigência cada vez maior de estruturas que ocupem menos espaço e sejam consideravelmente mais leves. No caso de passarelas de pedestres, a esbeltez da estrutura aliada a um baixo peso pode acarretar em problemas de vibrações devido à ressonância com o caminhar dos pedestres. Estes problemas podem variar desde uma simples sensação de desconforto até problemas mais graves como o colapso estrutural. Com base nestas premissas, esta dissertação visa investigar dois modelos estruturais, um em concreto armado e outro misto, do tipo aço concreto, onde os modelos serão estudados mediante o emprego do método dos elementos finitos através do programa ANSYS. Os modelos numéricos permitem determinar as frequências naturais da estrutura e consequentemente estudar as respostas dos modelos mediante análises de vibrações forçadas. As respostas dinâmicas da estrutura serão obtidas em termos dos valores dos deslocamentos máximos e das acelerações de pico. Os resultados obtidos foram comparados com os principais guias que regem o conforto humano no caso de caminhar de pessoas em passarelas de pedestres, de forma que houve indicativos de possíveis desconfortos após a análise dos resultados obtidos ao longo da investigação. Finalmente, foi feito um estudo considerando-se movimentos aleatórios dos pedestres sobre as passarelas, objetivando estudar os níveis da resposta dinâmica das estruturas nestas situações.
The structural engineer needs to adapt with the exigencies of low weight and less space occupied by the structures, which have been increasing more and more over the years. Related to footbridges, the structure slenderness and the low weight may lead to vibrations problems due to resonance with pedestrians walking. These problems may vary from a simple discomfort up to big problems, like the structural collapse. According to these premises, this dissertation aims to investigate two structural models, the first one in reinforced concrete and the other is related to a steel-concrete composite pedestrian footbridge, which will be analyzed by finite element method simulations using the software ANSYS. The numerical models make possible to evaluate the natural frequencies of structures and study the response due to forced vibrations induced by pedestrians walking. The dynamic responses of the investigated footbridges will be analyzed considering the maximum displacements and accelerations. The obtained results were compared with the main guidelines related to human comfort with regard to pedestrian walking on footbridges, in such a way that it showed possible problems due to vibrations, after analyzing the results obtained in the investigation. Thus, it was performed a study considering the variance of pedestrian position in order to analyze the dynamic response of the investigated footbridges in these cases.
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Jurík, Michal. "Lávky pro pěší tvořené plochým obloukem." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-392287.
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This doctoral thesis focuses on the research of the pedestrian bridges formed by the flat arch. To understand the basic static behaviour of the flat arch it was necessary to make a study of the development of the direct flat arch as footbridge with large span and the impact of stiffness on its camber. For the mathematical modeling FEM software ANSYS were used. The calculation has shown that a design of purely concrete flat arch would demand enormous bending stiffness, which can be achieved only through a massive cross-section. The findings gained in this chapter were further used to design a unique pedestrian bridge formed by the curved in plan flat arch, where to transfer of the large bending moments a steel pipe was designed. Several variants with different span and rise of the arch in plan were tested. From the tested variants was then selected footbridge with a span of 45 m and with the rise of the arch 10 m, which seemed to be the best solution according to the calculations and it was further analyzed in detail. The studied structure is formed by curved concrete slab that is stiffened through the steel brackets on the inner side of a steel tube with a graded thickness. The external cables that are situated in the handrail pipe balance the dead load torsional moment. Designed structure and the static analysis procedure were verified on a fully functional 1:6 scale model. The thesis describes the model analogy used for the design of the model, its structural design and its implementation. Load tests on the model confirmed correctness of the design of the proposed curved in plan pedestrian bridge, its high carrying capacity and the accuracy of the developed procedure of static analysis. Results and experiences acquired from the design and the realization of model are the basis for a practical realization of studied structures. The last part of the thesis deals with the possibility of replacement of the steel components with concrete in pedestrian bridges formed
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Koláček, Jan. "Analýza půdorysně zakřivených závěsných a visutých lávek." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-392289.
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The aim of the doctoral thesis focuses on the static and dynamic analysis of a plan curved cable stayed and suspension pedestrian bridges suspended on a single-side of their deck. The first part of this thesis deals with an analysis of the equilibrium in the transversal direction of a deck cross section suspended on a single-side. The section and its arrangement should be designed so that the torsion caused by the deck self-weight and dead load would be minimal. This theory was verified on a simple study of a single-sided suspended section with and without prestressing. Second part of the thesis deals with the design of a study of a plan curved cable stayed pedestrian bridge. The study describes in detail a finding of an initial state of the structure and the static and dynamic analysis performed by software ANSYS. The static analysis describes the response of the structure on the most frequent variable loads only, but not design of dimensioning according to the valid codes. The dynamic analysis verifies a predisposition of the structure to the vibrations and others harmful oscillation effects. The next objective of the thesis was to design a study of a plan curved suspension pedestrian bridge suspended on a single-side. A process of an analysis of these structures has not found in any available references. Especially, the finding of an initial state of a suspension cable has not been documented anywhere and by anybody. The study was analyzed with the same geometry as the cable stayed variation in order to compare both structures. The static and dynamic analysis was performed, too. The last part of the thesis describes the verification of structural solution on a fully functional model in a 1:10 scale, proposed process of the initial state finding, response of the structures on the loading and ultimate load test. The important step is the comparison of the results of the completed physical model and the calculation model.
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MANENTI, LORENZA ALESSANDRA. "Agent-based proxemic dynamics: crowd and groups simulation." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2013. http://hdl.handle.net/10281/42374.
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Considering the general overview on the Pedestrian Dynamics area, this thesis is focused in the area of pedestrian dynamics simulation, with the goal to study the phenomenon of groups as constitutive elements that compose a crowd, analyzing if their presence influences the dynamics of pedestrian flow and evaluating the impact of their contribution.
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Chraibi, Mohcine [Verfasser], Andreas [Akademischer Betreuer] Schadschneider, and Armin [Akademischer Betreuer] Seyfried. "Validated force-based modeling of pedestrian dynamics / Mohcine Chraibi. Gutachter: Andreas Schadschneider ; Armin Seyfried." Köln : Universitäts- und Stadtbibliothek Köln, 2012. http://d-nb.info/1038234409/34.
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GORRINI, ANDREA. "Empirical studies and computational results of a proxemic - based model of pedestrian crowd dynamics." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2014. http://hdl.handle.net/10281/50254.
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The thesis work is organized in two main parts. The first includes a review of the social science framework about crowd dynamics and proxemics, and the methodological approach. The second part consists of several empirical studies. A summary of the contents is provided as follows. Starting from the pioneering study of Gustave Le Bon (1897), the social science contributions about crowds are reviewed in Chapter 2 (Contagion-Transformation Theory, Elaborated Social Identity Model, Emergent Norm Theory, Affiliative Approach). Chapter 3 presents the proxemic theory, with reference to the notion of personal space and the group proxemic behavior in static and motion situations. Chapter 4 presents the methodological approach, as composed of: in vivo observation, in vitro experiments and in silico simulations. Chapter 5 proposed the results achieved by means of two observations performed at the Campus of the University of Milano-Bicocca (Italy) and the Vittorio Emanuele II gallery (Milan, Italy). Chapter 6 presents two experiments focused on the combined impact of turning path and grouping on pedestrian crowd dynamics and the size of pedestrian personal space. Chapter 7 presents a simulation campaign performed by using the platform MAKKSim. The results achieved have been compared with the collected empirical data for sake of model validation. The thesis ends with final remarks about the achieved results and future works towards the improvement of the computational model of MAKKSim.
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Sorrentino, Luigi. "Simulation and optimization of crowd dynamics using a multiscale model." Doctoral thesis, Universita degli studi di Salerno, 2012. http://hdl.handle.net/10556/318.
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2010 - 2011In the last decades, the modeling of crowd motion and pedestrian .ow has attracted the attention of applied mathematicians, because of an increasing num- ber of applications, in engineering and social sciences, dealing with this or similar complex systems, for design and optimization purposes. The crowd has caused many disasters, in the stadiums during some major sporting events as the "Hillsborough disaster" occurred on 15 April 1989 at Hills- borough, a football stadium, in She¢ eld, England, resulting in the deaths of 96 people, and 766 being injured that remains the deadliest stadium-related disaster in British history and one of the worst ever international football accidents. Other example is the "Heysel Stadium disaster" occurred on 29 May 1985 when escaping, fans were pressed against a wall in the Heysel Stadium in Brussels, Belgium, as a result of rioting before the start of the 1985 European Cup Final between Liv- erpool of England and Juventus of Italy. Thirty-nine Juventus fans died and 600 were injured. It is well know the case of the London Millennium Footbridge, that was closed the very day of its opening due to macroscopic lateral oscillations of the structure developing while pedestrians crossed the bridge. This phenomenon renewed the interest toward the investigation of these issues by means of mathe- matical modeling techniques. Other examples are emergency situations in crowded areas as airports or railway stations. In some cases, as the pedestrian disaster in Jamarat Bridge located in South Arabia, mathematical modeling and numerical simulation have already been successfully employed to study the dynamics of the .ow of pilgrims, so as to highlight critical circumstances under which crowd ac- cidents tend to occur and suggest counter-measures to improve the safety of the event. In the existing literature on mathematical modeling of human crowds we can distinguish two approaches: microscopic and macroscopic models. In model at microscopic scale pedestrians are described individually in their motion by ordinary di¤erential equations and problems are usually set in two-dimensional domains delimiting the walking area under consideration, with the presence of obstacles within the domain and a target. The basic modeling framework relies on classical Newtonian laws of point. The model at the macroscopic scale consists in using partial di¤erential equations, that is in describing the evolution in time and space of pedestrians supplemented by either suitable closure relations linking the velocity of the latter to their density or analogous balance law for the momentum. Again, typical guidelines in devising this kind of models are the concepts of preferred direction of motion and discomfort at high densities. In the framework of scalar conservation laws, a macroscopic onedimensional model has been proposed by Colombo and Rosini, resorting to some common ideas to vehicular tra¢ c modeling, with the speci.c aim of describing the transition from normal to panic conditions. Piccoli and Tosin propose to adopt a di¤erent macroscopic point of view, based on a measure-theoretical framework which has recently been introduced by Canuto et al. for coordination problems (rendez-vous) of multiagent systems. This approach consists in a discrete-time Eulerian macroscopic representation of the system via a family of measures which, pushed forward by some motion mappings, provide an estimate of the space occupancy by pedestrians at successive time steps. From the modeling point of view, this setting is particularly suitable to treat nonlocal interactions among pedestrians, obstacles, and wall boundary conditions. A microscopic approach is advantageous when one wants to model di¤erences among the individuals, random disturbances, or small environments. Moreover, it is the only reliable approach when one wants to track exactly the position of a few walkers. On the other hand, it may not be convenient to use a microscopic approach to model pedestrian .ow in large environments, due to the high com- putational e¤ort required. A macroscopic approach may be preferable to address optimization problems and analytical issues, as well as to handle experimental data. Nonetheless, despite the fact that self-organization phenomena are often visible only in large crowds, they are a consequence of strategical behaviors devel- oped by individual pedestrians. The two scales may reproduce the same features of the group behavior, thus providing a perfect matching between the results of the simulations for the micro- scopic and the macroscopic model in some test cases. This motivated the multiscale approach proposed by Cristiani, Piccoli and Tosin. Such an approach allows one to keep a macroscopic view without losing the right amount of .granularity,.which is crucial for the emergence of some self-organized patterns. Furthermore, the method allows one to introduce in a macroscopic (averaged) context some micro- scopic e¤ects, such as random disturbances or di¤erences among the individuals, in a fully justi.able manner from both the physical and the mathematical perspec- tive. In the model, microscopic and macroscopic scales coexist and continuously share information on the overall dynamics. More precisely, the microscopic part tracks the trajectories of single pedestrians and the macroscopic part the density of pedestrians using the same evolution equation duly interpreted in the sense of measures. In this respect, the two scales are indivisible. Starting from model of Cristiani, Piccoli and Tosin we have implemented algo- rithms to simulate the pedestrians motion toward a target to reach in a bounded area, with one or more obstacles inside. In this work di¤erent scenarios have been analyzed in order to .nd the obstacle con.guration which minimizes the pedes- trian average exit time. The optimization is achieved using to algorithms. The .rst one is based on the exhaustive exploration of all positions: the average exit time for all scenarios is computed and then the best one is chosen. The second algorithm is of steepest descent type according to which the obstacle con.guration corresponding to the minimum exit time is found using an iterative method. A variant has been introduced to the algorithm so to obtain a more e¢ cient proce- dure. The latter allows to .nd better solutions in few steps than other algorithms. Finally we performed other simulations with bounded domains like a classical .at with .ve rooms and two exits, comparing the results of three di¤erent scenario changing the positions of exit doors. [edited by author]
X n.s.
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Mendes, Joesley Pereira. "Análise dinâmica e controle de vibrações de passarelas de pedestres submetidas ao caminhar humano." Universidade do Estado do Rio de Janeiro, 2014. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=7465.
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Fundação de Amparo à Pesquisa do Estado do Rio de JaneiroPassarelas de pedestres mistas (aço-concreto) e de aço são frequentemente submetidas a ações dinâmicas de magnitude variável, devido à travessia de pedestres sobre a laje de concreto. Estas ações dinâmicas podem produzir vibrações excessivas e dependendo de sua magnitude e intensidade, estes efeitos adversos podem comprometer a confiabilidade e a resposta do sistema estrutural e, também, podem levar a uma redução da expectativa de vida útil da passarela. Por outro lado, a experiência e o conhecimento dos engenheiros estruturais em conjunto com o uso de novos materiais e tecnologias construtivas têm produzido projetos de passarelas mistas (aço-concreto) bastante arrojados. Uma consequência direta desta tendência de projeto é um aumento considerável das vibrações estruturais. Com base neste cenário, esta dissertação visa investigar o comportamento dinâmico de três passarelas de pedestres mistas (aço-concreto) localizadas no Rio de Janeiro, submetidas ao caminhar humano. Estes sistemas estruturais são constituídos por uma estrutura principal de aço e laje em concreto e são destinados à travessia de pedestres. Deste modo, foram desenvolvidos modelos numérico-computacionais, adotando-se as técnicas tradicionais de refinamento presentes em simulações do método de elementos finitos, com base no uso do software ANSYS. Estes modelos numéricos permitiram uma completa avaliação dinâmica das passarelas investigadas, especialmente em termos de conforto humano. As respostas dinâmicas foram obtidas em termos de acelerações de pico e comparadas com valores limites propostas por diversos autores e normas de projeto. Os valores de aceleração de pico e aceleração rms encontrados na presente investigação indicaram que as passarelas analisadas apresentaram problemas relacionados com o conforto humano. Assim sendo, considerando-se que foi detectado que estas estruturas poderiam atingir níveis elevados de vibração que possam vir a comprometer o conforto dos usuários, foi verificado que uma estratégia para o controle estrutural era necessária, a fim de reduzir as vibrações excessivas nas passarelas. Finalmente, uma investigação foi realizada com base em alternativas de controle estrutural objetivando atenuar vibrações excessivas, a partir do emprego de sistemas de atenuadores dinâmicos sintonizados (ADS).
Steel and steel-concrete composite pedestrian footbridges are frequently subjected to dynamic actions with variable magnitudes due to the pedestrian crossing on the concrete deck. These dynamic actions can produce excessive vibrations and depending on their magnitude and intensity, these adverse effects can compromise the structural systems response and its reliability and may also lead to a reduction of the expected footbridge service life. The structural engineers experience and knowledge together with the use of newly developed materials and technologies have produced steel-concrete composite daring footbridges. A direct consequence of this design trend is a considerable increase of structural vibrations. Based on this scenario, this dissertation aims to investigate the dynamic behaviour of three steel-concrete composite pedestrian footbridge submitted to human walking vibration, located at Rio de Janeiro. These structural systems are composed by steel structure and a concrete slab and are destined for pedestrian crossing. Computational models were developed adopting the usual mesh refinement techniques present in finite element method simulations using ANSYS software. These numerical models have enabled a complete dynamic evaluation of the investigated footbridges especially in terms of human comfort and its associated vibration serviceability limit states. The dynamic responses were obtained in terms of peak accelerations and were compared to the limiting values proposed by authors and design standards. The peak acceleration values found in the present investigation indicated that the analysed footbridges have presented problems related to human comfort. Considering that it was detected that these structures could reach high vibration levels that might compromise the footbridge users comfort, it was proposed a structural control system in order to reduce the excessive vibrations. Thus, an investigation was performed based on some structural control alternatives for attenuating excessive vibrations using tuned mass damper (TMD) systems.
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Eilhardt, Christian [Verfasser], Andreas [Akademischer Betreuer] Schadschneider, and Armin [Akademischer Betreuer] Seyfried. "Computer simulation of pedestrian dynamics at high densities / Christian Eilhardt. Gutachter: Andreas Schadschneider ; Armin Seyfried." Köln : Universitäts- und Stadtbibliothek Köln, 2014. http://d-nb.info/1069985767/34.
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Peng, Yong. "In-depth accident investigation of pedestrian impact dynamics and development of head injury risk functions." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAD024.
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Les piétons comptent parmi les usagers de la route les plus vulnérables dans la mesure où ils ne bénéficient d'aucune protection en cas d'impact avec un véhicule automobile. Plus de 1,17 millions de personnes sont tués sur la route de part le monde dont environ 65% ce piétons. Les blessures de la tête, souvent fatales, concernent environ 30 % des blessures enregistrées. Ces blessures conduisent à des incapacités de longue durée avec un coût sociétal et économique immense. Il est par conséquent essentiel de comprendre aussi bien les mécanismes d'accidents que les mécanismes de blessure de la tête afin d'intervenir sur la conception de la face avant des véhicules automobile. Dans ce contexte l'objet de la présente thèse est d'analyser la répons dynamique du piton en cas d'accident et ce contribuer au développement de critères de blessure de la tête. Dans le but d'étudier l'influence de la position du piéton, de la géométrie de la face avant du véhicule et de sa vitesse initiale sur la cinématique du piéton et les conditions d'impact de la tête, une simulation multi-corps a été mise en place. Les résultats de ces simulations donnent la vitesse et l'angle d'impact de la tête et la position de l'impact sur le véhicule. Cette analyse paramètrique a été conduite sur cinq types de véhicules et pour un modèle humain adulte et enfant de 6 ans et a permis de consolider les connaissances sur la conditions d'impact de la tête en comparaison avec les tests normatifs en vigueur.[...]Pedestrians are regarded as an extremely vulnerable and high-risk group of road users since they are unprotected in vehicle impacts. More than 1.17 million people throughout the world are killed in road traffic accidents each year. Where, about 65% of deaths involve pedestrians. The head injuries in vehicle-pedestrian collisions accounted for about 30% of all reported injuries on different body regions, which often resulted in a fatal consequence. Such injuries can result in disabilities and long-term sequence, which lead to significant social costs. It is therefore important to study the characteristics of pedestrian accidents and understand the head injury mechanism of the pedestrian so as to improve vehicle design for pedestrian protection. The aim of this study is to investigate pedestrian dynamic response and develop head injury risk functions.In order to investigate the effect of pedestrian gait, vehicle front geometry and impact velocity on the dynamic responses of the head, the multi-body dynamic (MBD) models were used to simulate the head responses in vehicle to pedestrian collisions with different vehicle types in terms of head impact point measured with Wrap Around Distance (WAD), head relative velocity and impact angle. A simulation matrix is established using five vehicle types, and two mathematical models of the pedestrians represented a 50th male adult and a 6 year old child as well as seven pedestrian gaits based on typical postures in pedestrian accidents. In order to simulate a large range of impact conditions, four vehicle velocities (30 km/h, 40 km/h, 50 km/h and 60 km/h) are considered for each pedestrian position and vehicle type.A total of 43 passenger car versus pedestrian accidents were selected from In-depth Investigation of Vehicle Accidents in Changsha, China (IVAC) and German In-Depth Accident Study (GIDAS) database for simulation study. According to real-world accident investigation, accident reconstructions were conducted using multi-body system (MBS) pedestrian and car models under MADYMO simulation environment to calculate head impact conditions, in terms of head impact velocity, head position and head orientation. In order to study kinematics of adult pedestrian, relationship curves: head impact time, throw distance, head impact velocity and vehicle impact velocity, were computed and logistic regression models: head impact velocity, resultant angular velocity, HIC value, head contact force and head injuries, were developed based on the results from accident reconstructions.The automobile windshield, with which pedestrians come into frequent contact, has been identified as one of the main contact sources for pedestrian head injuries. In order to investigate the mechanical behavior of windshield laminated glass in the caseof pedestrian head impact, windshield FE models were set up using different combination for the modeling of glass and PVB, with various connection types and two mesh sizes (5 mm and 10 mm). Each windshield model was impacted with a standard adult headform impactor in an LS-DYNA simulation environment, and the results were compared with the experimental data reported in the literatures.In order to assess head injury risks of adult pedestrians, accident reconstructions were carried out by using Hybrid III head model based on the real-world pedestrian accidents. The impact conditions were obtained from the MBS simulation, including head impact velocity, head position and head orientation. They were used to set the initial conditions in a simulation of a Hybrid III FE head model striking a windshield FE model. Logistic regression models, Skull Fracture Correlate (SFC), head linear acceleration, Head Impact Power (HIP), HIC value, resultant angular acceleration and head injuries, were developed to study brain injury risk.{...]
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KHAN, SULTAN DAUD. "Automatic Detection and Computer Vision Analysis of Flow Dynamics and Social Groups in Pedestrian Crowds." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/102644.
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Computer vision played a vital role in the field of video surveillance. However, recent developed computer vision algorithms rarely solve the problems related to real time crowd management. The phenomena of crowd like sports, festivals, concerts, political gatherings etc, are mostly observed in urban areas, which attracts hundreds of thousands people. In this thesis, we have developed algorithms that overcome some of the challenges encountered in videos of crowded environments such as sporting events, religious festivals, parades, concerts, train stations, airports, and malls. The main theme of this thesis is two fold ,i.e, understanding crowd dynamics in videos of (i), high density crowds and (ii) low density crowds. Typical examples of high density crowds include marathons, religious festivals while malls, airports, subways etc covers low dense situations. In this thesis, we adopt different approaches in order to deal with different kinds of problems coming from these two categories of crowd.
In particular, first part of the thesis, we adopt holistic approach to generate a global representation of the scene that captures both dynamics of the crowd and structure of the scene. This was achieved by extracting global features, i.e optical flow from the scene. For the crowd flow segmentation problem, the optical flows vectors are clustered by using K-means clustering followed by the blob absorption approach. Using the segmentation information, we continue to estimate the number of people in each segment by carrying out the blob analysis and blob size optimization approach. This approach however, provide useful information for understanding crowd dynamics yet it lacks significant information for understanding crowd behavior. Therefore, in this thesis, the current crowd flow segmentation and counting approach is further extended in order to coup the challenges of crowd behavior understanding. The extension adopts optical flow for the identification of pedestrian movements, and it considers the analyzed video as a set of sequences. The latter are analyzed separately, producing tracklets that are then clustered to produce global trajectories, defining both sources and sinks, but also characterizing the movement of pedestrians in the scene.
In the second part of the thesis, We propose a novel approach for automatic detection of social groups of pedestrians in crowds by considering only start (source) and stop (sink) locations of pedestrian trajectories. We build an Association Matrix that captures the joint probability distribution of starts and stops locations of all pedestrian trajectories to all other pedestrian trajectories in the scene. Pedestrians exhibiting similar distribution are combining in a group, where as similarity among the distributions is measuread by KL Divergence We adopt bottom-up hierarchical clustering approach, which is three step processes. In first step, we treat all the individuals as independent clusters, In the second step, couples are detected and after pruning of bad couples, Adjacency matrix is generated. Later on, in step three, using the Adjacency Matrix, groups of couples, those have strong intergroup closeness (similarity) are merged into a larger group..
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Williams, David. "Vehicle dynamics and personal exposure to black carbon in the vicinity of at-grade pedestrian infrastructure." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/24158.
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Urban areas are often subject to traffic-induced poor air quality. Variability in vehicle operating behaviours at traffic management infrastructure leads to increased emission rates of pollutant species harmful to health. Where these locations are also sites of pedestrian activity, exposure to pollution is increased. This thesis demonstrates this mechanism through measurement of vehicle dynamics and emissions modelling, with tailpipe emissions found to be at least 20% greater when the vehicle is delayed due to mid-link crossings. As it has no non-combustion sources, black carbon (BC) is a useful proxy for traffic related emissions. Previous research into air quality at traffic management infrastructure has been of an insufficient scale to identify the variability in pollutant concentration and exposure. This thesis addresses this gap through an investigation into BC concentration and exposure at traffic management infrastructure, demonstrating that fixed monitors over coarse temporal and spatial scales are inadequate for assessing BC concentration and exposure, and finding that public health and transport professionals are ill-equipped to make recommendations for improvements on the basis of current data and understanding. To provide data suitable for an assessment at the micro-scale, a measurement framework is specified for the use of micro-aethalometers in urban areas. This addresses problems of signal noise, aerosol loading and consistency where other studies have not, enabling measurement of BC concentration at higher temporal resolution (5-second) than previously. Micro-aethalometers are deployed at signalised intersections in London and Glasgow (UK). The variability in BC is identified, with median concentration up to 130% greater at pedestrian waiting locations across the intersection. In high traffic flow environments, the periodicity of peak concentration episodes is found to relate to traffic control cycles. High-resolution data are applied to pedestrian exposure studies, with in-transit exposure to BC varying by more than ten times as a result of activity patterns.
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Cheng, Lin. "Modelling airport passenger group dynamics using an agent-based method." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/72999/1/Lin_Cheng_Thesis.pdf.
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This thesis investigates the influence of passenger group dynamics on passengers' behaviour in an international airport. A simulation model is built to analyse passengers' behaviour during airport departure processes and during an emergency event. Results from the model showed that passengers' group dynamics have significant influences on the performance and utilisation of airport services. The agent-based model also provides a convenient way to investigate the effectiveness of space design and service allocations, which may contribute to the enhancement of passenger airport experiences.
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Zúñga, José Eduardo Villarroel. "Análise da resposta dinâmica experimental de uma passarela tubular mista, aço-concreto, submetida ao caminhar humano." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=5531.
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Este trabalho de pesquisa apresenta como objetivo principal o desenvolvimento de investigação experimental dinâmica sobre estrutura real de uma passarela tubular mista aço-concreto. O sistema estrutural objeto deste trabalho corresponde a uma passarela composta por três vãos (32,5m, 17,5m e 20,0m, respectivamente) e dois balanços (7,50m e 5,0m, respectivamente), com comprimento total de 82,5m. A passarela com estrutura contínua de aço com as ligações soldadas se apoia em quatro pórticos também de aço. Estruturalmente está constituída por duas treliças planas que se interligam através de contraventamentos horizontais fixados na corda superior e inferior da treliça e lajes de concreto, formando um sistema misto com interação completa. A estrutura está submetida correntemente à travessia de pedestres e ciclistas. Testes experimentais foram realizados sobre o sistema estrutural e confrontados com resultados numéricos. Para a modelagem numérica do sistema são empregadas técnicas usuais de discretização, via método dos elementos finitos (MEF), por meio do programa ANSYS. Os resultados experimentais são analisados de acordo com a metodologia desenvolvida, sendo realizada análise modal experimental para a determinação das propriedades dinâmicas: freqüências, modos e taxa de amortecimento, enquanto que os resultados da estrutura, em termos de aceleração de pico, são comparados com os valores limites propostos por diversos autores, normas e recomendações de projeto, para uma avaliação do desempenho da estrutura em relação a vibração quando solicitada pelo caminhar dos pedestres no que diz respeito a critério para conforto humano.This research has as main objective the development of a dynamical experimental investigation of a real structure a tubular composite steel-concrete footbridge. The structural system of this study corresponds to a footbridge composed by three spans (32,5m, 17,5m and 20,0m, respectively) and two overhangs (7,50m and 5,0m, respectively), spanning 82,5m. The investigated structural model is composed by a continuous tubular steel structure with welded connections supported by four double file steel columns. It is structurally composed of two plane trusses are intertwined by horizontal bracing set in upper and lower chord of the truss and slabs of concrete, forming effective composite with complete interaction. This structure is currently submitted to pedestrians and cyclists crossing. Experimental tests were carried out on the structural system and with the numerical results. For the numerical modeling, discretization techniques via finite element method were applied, based on the ANSYS program. The experimental results were analyzed according to the developed methodology, and a modal analysis was implemented to determine the dynamical properties: frequencies, mode shapes and modal damping ratio, while the structure results in terms of peak acceleration, was obtained and compared to the limit values proposed by several authors and design recommendations, for the structure performance by pedestrian walking regarding the acceptance criteria for human comfort.
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Al-nasur, Sadeq J. "New Models for Crowd Dynamics and Control." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/30107.
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In recent years, there has been an increasing interest in modeling crowd and evacuation dynamics. Pedestrian models are based on macroscopic or microscopic behavior. In this work, we are interested in developing models that can be used for evacuation control strategies. Hence, we use macroscopic modeling approach, where pedestrians are treated in an aggregate way and detailed interactions are overlooked. In this dissertation, we developed two-dimensional space crowd dynamic models to allow bi-directional low by modifying and enhancing various features of existing traffic and fluid dynamic models. In this work, four models based on continuum theory are developed, and conservation laws such as the continuity and momentum equations are used. The first model uses a single hyperbolic partial differential equation with a velocity-density relationship, while the other three models are systems of hyperbolic partial differential equations. For one of the system models presented, we show how it can be derived independently from a microscopic crowd model. The models are nonlinear, time-varying, hyperbolic partial differential equations, and the numerical simulation results given for the four macroscopic models were based on computational fluid dynamics schemes.
We also started an initial control design that synthesizes the feedback linearization method for the one-dimensional traffic flow problem applied directly on the distributed parameter system. In addition, we suggest and discuss the information technology requirements for an evacuation system.
This research was supported in part from the National Science Foundation through grant no. CMS-0428196 with Dr. S. C. Liu as the Program Director. This support is gratefully acknowledged. Any opinion, findings, and conclusions or recommendations expressed in this study are those of the writer and do not necessarily reflect the views of the National Science Foundation.Ph. D.
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Bain, Nicolas. "Hydrodynamics of polarized crowds : experiments and theory." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN078/document.
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Modéliser le mouvement des foules humaines est essentiel pour des situations aussi diverses que la prévention de risque dans les lieux publics, la planification d’évènements ou la création d’animations visuelles réalistes. Cependant, la difficulté de mener des expériences quantitatives limite notre compréhension de la dynamique des piétons, et le manque de mesures de référence rend impossible une comparaison poussée des modèles existants. Cette thèse tente d’augmenter notre compréhension des foules humaines par deux approches distinctes. Dans un premier temps, nous avons conduit une étude numérique et théorique pour étudier formation de lignes au sein de flux bidirectionnels d'agents motiles. Nous avons montré qu’une transition de phase critique du second ordre séparait un état mélangé d’un état constitué de lignes géantes le long desquelles se déplacent les agents visants une même direction. Cette séparation est caractéristique des systèmes actifs. Une approche hydrodynamique nous a ensuite permis de prouver que les phases mélangées sont aussi algébriquement corrélées dans la direction longitudinale. Nous avons expliqué et montré que ces fortes corrélations sont génériques de tous systèmes de flux bidirectionnels, qu’ils soient constitués de particules forcées ou de particules actives. Dans un second temps, nous avons mené une campagne expérimentale de grande envergure afin d’établir une expérience de référence des foules humaines. Nous avons pour cela choisi un système modèle, la zone d’attente de marathons. Dans ces foules de dizaines de milliers d’individus, nous avons quantitativement établi que les fluctuations de vitesse se propagent sur de grandes échelles, alors que les variations d’orientation s’évanouissent en quelques secondes. Grâce à ces mesures, nous avons construit une théorie prédictive hydrodynamique des foules polariséesModelling crowd motion is central to situations as diverse as risk prevention in mass events and visual effects rendering in the motion picture industry. The difficulty to perform quantitative measurements in model experiments, and the lack of reference experimental system, have however strongly limited our ability to model and control pedestrian flows. The aim of this thesis is to strengthen our understanding of human crowds, following two distinct approaches.First, we designed a numerical model to study the lane formation process among bidirectional flows of motile particles. We first evidenced the existence of two distinct phases: one fully laned and one homogeneously mixed, separated by a critical phase transition, unique to active systems. We then showed with a hydrodynamic approach that the mixed phase is algebraically correlated in the direction of the flow. We elucidated the origin of these strong correlations and proved that they were a universal feature of any system of oppositely moving particles, active of passive.Second, we conducted a substantial experimental campaign to establish a model experiment of human crowds. For that purpose we performed systematic measurements on crowds composed of tens of thousands of road-race participants in start corrals, a geometrically simple setup. We established that speed information propagates through polarized crowds over system spanning scales, while orientational information is lost in a few seconds. Building on these observations, we laid out a hydrodynamic theory of polarized crowds and demonstrated its predictive power
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Řehová, Jana. "Analýza dynamického chování štíhlé mostní konstrukce a návrh zařízení na omezení vibrací." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2020. http://www.nusl.cz/ntk/nusl-409744.
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This master thesis deals with the dynamic analysis of a footbridge. Computational model of the footbridge was created using ANSYS software. The model was subjected to dynamic wind load in longitudal and lateral direction. Furthermore pedestrian load in lateral direction was analyzed. Afterwards, due to unsatisfactory response to the pedestrian laod, a tuned mass damper was introduced to reduce the vibration. This lead to decrease in the vibration to a satisfactory levels, as is shown in the analyses of the model.